1. Field of the Invention
The present invention relates to an improved method for measuring the temperature of an object and also includes the apparatus used to implement this method.
2. State of the Art
When, for example, a piece of steel or other metal is heated for such purposes as hot working or heat treatment, it is not easy to accurately measure the temperature of the piece. In cases where the steel materials are heated in a heating furnace it has been common to measure the temperature of the furnace wall or the temperature of the furnace atmosphere instead of the temperature of the object. But in cases where this is not satisfactory, a radiation thermometer of an apparatus for determining the temperature of an object by measuring the intensity of infrared rays radiating from it is being widely used.
However, in ordinary furnaces using fuel gases or heavy oil, smoke or dust particles, or oxide scales are in ambient suspension. Because the burner flame emits strong infrared rays, and also because the suspended particles attenuate infrared rays emitting from the object being measured, both become sources of error in measurement. To solve this, a method being practiced is to position water-cooling pipes, provided with a canopy, close to the object being measured, in order to protect the passageway of the radiated infrared rays from the error factors. Nevertheless, when the water-cooling pipes are used to try to satisfactorily obtain this result, the temperature of the surrounding area falls and an accurate temperature can not be obtained.